Concurrent handover configuration

Abstract

A solution for handling concurrent handover configurations is provided. According to one aspect, a method includes receiving, by a distributed unit, a measurement report for a user equipment; determining, by the distributed unit, to initiate an intra-centralized unit handover procedure based on the received measurement report, wherein the initiating includes transmitting, by the distributed unit, a message to a centralized unit controlling the distributed unit to block concurrent intra-centralized unit handover procedures and inter-centralized unit handover procedures for the user equipment; and performing, by the distributed unit with the user equipment, the intra-centralized unit handover procedure or cancelling the initiated intra-centralized unit handover procedure based on the transmitting the message.

Description

Technical Field

[0001] The various example embodiments generally relate to cellular communication systems with multiple handover scenarios. Background Technology

[0002] In modern cellular communication systems, various mobility control options are provided for user equipment (UE). As a UE moves, its connection to the radio access network is transferred (handed over) from one radio access network node to another. There are several handover options, such as: "regular" Layer 3 handover performed by network command handover; conditional handover where the network sets conditions and the UE can autonomously trigger the handover execution under these conditions; and Layer 1 / Layer 2 triggered mobility (LTM), where serving cell handover is moved down to below Layer 3, and the handover (or serving cell handover) execution can be triggered via Media Access Control (MAC) signaling. Summary of the Invention

[0003] The subject matter of the independent claims is provided according to several aspects. Additional aspects are defined in the dependent claims. Embodiments not falling within the scope of the claims are to be interpreted as examples useful for understanding this disclosure.

[0004] According to one aspect, an apparatus for a distributed unit is provided, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive a measurement report for a user equipment; determine, based on the received measurement report, to initiate an intra-unit handover process, wherein initiation includes sending a message to a centralized unit controlling the distributed unit, the message being used to prevent concurrent intra-unit handover processes and inter-unit handover processes for the user equipment; and, based on sending the message, performing the intra-unit handover process with the user equipment, or canceling the initiated intra-unit handover process.

[0005] In an embodiment, the device is configured to perform a handover process within a central unit in the absence of a response to the message from the central unit.

[0006] In an embodiment, the device is configured to wait for confirmation from the central unit when sending a message, and to execute the intra-central unit handover process when it is determined that the confirmation indicates that the central unit has approved the intra-central unit handover process.

[0007] In an embodiment, the device is configured to wait for confirmation from the central unit when sending a message, and to cancel the intra-central unit handover process when it is determined that the confirmation indicates that the central unit rejects the intra-central unit handover process.

[0008] In an embodiment, the device is further configured to receive a second message from a central unit, the second message being used to prevent concurrent intra-central unit switching processes and inter-central unit switching processes, and to cancel intra-central unit switching processes or another intra-central unit switching process.

[0009] In one embodiment, the device is also configured to associate a measurement report with a timestamp and include the timestamp in the message.

[0010] According to one aspect, an apparatus for a central unit is provided, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive a message from a distributed unit controlled by the central unit, the message indicating that the distributed unit intends to perform an intra-central unit handover process with a user equipment; receive a measurement report for the user equipment, the measurement report indicating an inter-central unit handover process; perform the inter-central unit handover process based on the timing of the message and the measurement report, based on the received measurement report, and send a second message to the distributed unit, the second message being used to prevent concurrent intra-central unit handover processes and inter-central unit handover process second messages of the user equipment, or to determine not to perform the inter-central unit handover process to allow the intra-central unit handover process indicated by the message.

[0011] In an embodiment, if a measurement report is received before the message, the device is configured to perform a central unit handover process based on the received measurement report, wherein the second message is a response to a message received from the distributed unit, and wherein the second message indicates that the central unit refuses to perform a central unit handover process, the central unit handover process being indicated by a message received from the distributed unit.

[0012] In an embodiment, if a measurement report is received before the message, the device is configured to perform an inter-central unit handover process based on the received measurement report, and wherein the second message is an indication to the distributed unit that the central unit is performing a handover process for a user equipment, and the second message prevents the distributed unit from initiating a concurrent intra-central unit handover process.

[0013] In one embodiment, if the message is received before the measurement report, the device is configured to determine, based on the received measurement report, not to perform a central unit switching process.

[0014] In one embodiment, the device is configured to send an acknowledgment in response to the message indicating that the switching process within the central unit has been approved.

[0015] In one embodiment, the message includes a timestamp indicating the timing of a second measurement report received by a distributed unit and triggering a handover process within a centralized unit, wherein the device is configured to compare the timestamp with the timing of a measurement report indicating a handover process between centralized units, and to determine, based on the comparison, whether to perform a handover process between centralized units.

[0016] In one embodiment, both the intra-unit handover process and the inter-unit handover process are the same type of handover process: conditional handover process, layer 3 handover process, or layer 1 / layer 2 triggered mobility.

[0017] According to one aspect, a method is provided, comprising: a distributed unit receiving a measurement report for a user equipment; the distributed unit determining, based on the received measurement report, to initiate an intra-unit handover process, wherein initiation includes sending a message to a centralized unit controlling the distributed unit, the message being used to prevent concurrent intra-unit handover processes and inter-unit handover processes of the user equipment; and based on the sent message, the distributed unit and the user equipment performing an intra-unit handover process, or canceling the initiated intra-unit handover process.

[0018] In an embodiment, if there is no response to the message from the central unit, the distribution unit performs a handover process within the central unit.

[0019] In this embodiment, when the distribution unit sends a message, it waits for confirmation from the central unit, and when it determines that the confirmation indicates the central unit has approved the handover process within the central unit, it executes the handover process within the central unit.

[0020] In this embodiment, when sending a message, the distribution unit waits for confirmation from the central unit, and cancels the handover process within the central unit when it determines that the confirmation indicates the central unit to reject the handover process within the central unit.

[0021] In an embodiment, the method further includes receiving a second message from the central unit by the distributed unit, the second message being used to prevent concurrent intra-central unit switching processes and inter-central unit switching processes, and to cancel intra-central unit switching processes or another intra-central unit switching process.

[0022] In one embodiment, the distribution unit associates the measurement report with a timestamp and includes the timestamp in the message.

[0023] According to one aspect, a method is provided, comprising: receiving a message from a distribution unit controlled by the central unit, the message indicating that the distribution unit intends to perform an intra-central-unit handover process with a user equipment; receiving a measurement report for the user equipment, the measurement report indicating an inter-central-unit handover process; based on the timing of the message and the measurement report, performing the inter-central-unit handover process based on the received measurement report, and sending a second message to the distribution unit, the second message being used to prevent concurrent intra-central-unit handover processes and inter-central-unit handover processes of the user equipment, or determining by the central unit not to perform the inter-central-unit handover process in order to allow the intra-central-unit handover process indicated by the message to be performed.

[0024] In an embodiment, if a measurement report is received before the message, the central unit performs a central unit handover process based on the received measurement report, wherein the second message is a response to a message received from the distribution unit, and wherein the second message indicates that the central unit refuses to perform a central unit handover process, the central unit handover process being indicated by a message received from the distribution unit.

[0025] In an embodiment, if a measurement report is received before the message, the central unit performs a handover process between central units based on the received measurement report, and the second message is an indication to the distributed unit that the central unit is performing a handover process for a user equipment, and the second message prevents the distributed unit from initiating a concurrent handover process within the central unit.

[0026] In an embodiment, if the message is received before the measurement report, the central unit determines not to perform the central unit switching process based on the received measurement report.

[0027] In one embodiment, the central unit responds to the message by sending an acknowledgment indicating that the handover process within the central unit has been approved.

[0028] In one embodiment, the message includes a timestamp indicating the timing of a second measurement report received by a distributed unit and triggering a handover process within a centralized unit, wherein the centralized unit compares the timestamp with the timing of a measurement report indicating a handover process between centralized units, and determines, based on the comparison, whether to perform a handover process between centralized units.

[0029] In one embodiment, both the intra-unit handover process and the inter-unit handover process are the same type of handover process: conditional handover process, layer 3 handover process, or layer 1 / layer 2 triggered mobility.

[0030] According to one aspect, a computer program product is provided, embodied on a computer-readable distribution medium and including program instructions that, when executed by a device, cause the device to perform a method according to any of the embodiments described above.

[0031] Some embodiments of the present invention are defined in the dependent claims. Attached Figure Description

[0032] In the following description, the invention will be described in more detail with reference to embodiments and accompanying drawings, wherein: Figure 1A and Figure 1B This illustrates network and communication scenarios to which one or more embodiments are applicable; Figure 2 and Figure 3 An example of a process for managing concurrent switching configurations according to one embodiment is shown; Figure 4A and Figure 4B An embodiment of a notification-based configuration for preventing concurrent handover in a radio access network is illustrated; Figure 5A and Figure 5B An embodiment of an acknowledgment-based configuration for preventing concurrent handover in a radio access network is illustrated; Figure 6 A process for managing concurrent handover configurations in a user equipment is illustrated according to one embodiment; Figure 7 An embodiment of a procedure for modifying the execution conditions of a switching configuration in a concurrent switching configuration is shown; Figure 8A and Figure 8B An example is shown whereby a user equipment indicates the selected handover configuration to the radio access network; Figure 9 and Figure 10 An apparatus according to some embodiments is shown. Detailed Implementation

[0033] The following embodiments are exemplary. Although the specification may refer to "a," "an," or "some" (or more) embodiments in several places in the text, this does not necessarily mean that the same (or more) embodiments are mentioned each time, nor does it mean that a particular feature is applicable only to a single embodiment. Individual features of different embodiments may also be combined to provide other embodiments. For the purposes of this disclosure, the phrases "at least one of A or B," "at least one of A and B," and "A and / or B" mean (A), (B), or (A and B). For the purposes of this disclosure, the phrases "A or B" and "A and / or B" mean (A), (B), or (A and B). For the purposes of this disclosure, the phrases "A, B, and / or C" mean (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C).

[0034] It should be understood that although the terms "first" and "second," etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0035] The described embodiments can be implemented in radio systems, such as those including at least one of the following radio access technologies (RATs): Global Microwave Access Interoperability (WiMAX), Global System for Mobile Communications (GSM, 2G), GSM EDGE Radio Access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunications System based on Basic Wideband Code Division Multiple Access (W-CDMA) (UMTS, 3G), High-Speed ​​Packet Access (HSPA), Long Term Evolution (LTE), Advanced Long Term Evolution, and Enhanced LTE (eLTE). The term "eLTE" here refers to LTE evolution connected to a 5G core. LTE is also known as Evolved UMTS Terrestrial Radio Access (EUTRA) or Evolved UMTS Terrestrial Radio Access Network (EUTRAN). The term "resource" can refer to radio resources, such as physical resource blocks (PRBs), radio frames, subframes, time slots, subbands, frequency regions, subcarriers, beams, etc. The terms "transmit" and / or "receive" can refer to wireless transmission and / or reception on radio resources via a radio propagation channel.

[0036] However, the embodiments are not limited to the system / RAT given as an example, and those skilled in the art can apply the solution to other communication systems / networks with the necessary attributes. Some examples of suitable communication networks include 5G and / or 6G networks. 3GPP's 5G solution is called New Radio (NR). 6G is envisioned as a further development of 5G. NR is envisioned to use multiple-input multiple-output (MIMO) multi-antenna transmission technology, deploy more base stations or nodes than current LTE networks (the so-called small cell concept), including macro sites working in conjunction with smaller local access nodes, and may also employ various radio technologies to achieve better coverage and enhanced data rates. 5G may consist of more than one radio access technology / radio access network (RAT / RAN), each optimized for specific use cases and / or spectrum. 5G mobile communications can have a wider range of use cases and related applications, including video streaming, augmented reality, different data sharing methods, and various forms of machine-type applications, including vehicle safety, different sensors, and real-time control. 5G is expected to have multiple radio interfaces, namely sub-6GHz, cmWave and mmWave, and can be integrated with existing traditional radio access technologies such as LTE.

[0037] The current architecture in LTE networks is distributed on the radio side but centralized in the core network. Low-latency applications and services in 5G may require moving content closer to the radio side, leading to local offloading and multi-access edge computing (MEC). 5G enables analytics and knowledge generation at the data source. This approach requires leveraging resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC provides a distributed computing environment for application and service hosting and can also store and process content near cellular subscribers to reduce response times. Edge computing encompasses a wide range of technologies, such as wireless sensor networks, mobile data acquisition, mobile signature analytics, collaborative distributed peer-to-peer self-organizing networking and processing (also categorized as local cloud / fog computing and grid / mesh computing), exposed computing, mobile edge computing, micro-cloud, distributed data storage and retrieval, autonomous and self-healing networks, remote cloud services, augmented reality and virtual reality, data caching, the Internet of Things (IoT) (massive connectivity and / or latency critical), and critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications). Edge cloud can be introduced into the RAN by leveraging Network Functions Virtualization (NVF) and Software-Defined Networking (SDN). Using edge cloud means performing access node operations, at least partially, in servers, hosts, or nodes coupled to remote radio heads or base stations including radio sections. Network slicing allows the creation of multiple virtual networks over a shared physical infrastructure, which can then be customized to meet the specific needs of applications, services, devices, customers, or operators.

[0038] In radio communications, node operations can be performed at least partially in a central / centralized unit (CU), (e.g., a server, host, or node), which is operationally coupled to distributed units (DUs), (e.g., radio headends / nodes). Node operations may also be distributed among multiple servers, nodes, or hosts. It should also be understood that the workload distribution between core network operations and base station operations can vary depending on the implementation. Therefore, 5G network architectures can be based on so-called CU-DU splitting. One gNB-CU controls multiple gNB-DUs. The term "gNB" in 5G may correspond to the eNB in ​​LTE. One or more gNBs can communicate with one or more UEs. The gNB-CU (central node) can control multiple spatially separated gNB-DUs, which at least act as transmit / receive (Tx / Rx) nodes. However, in some embodiments, the gNB-DU (also known as DU) may include, for example, the Radio Link Control (RLC), Media Access Control (MAC) layer, and Physical (PHY) layer, while the gNB-CU (also known as CU) may include layers above the RLC layer, such as the Packet Data Convergence Protocol (PDCP) layer, Radio Resource Control (RRC) layer, and Internet Protocol (IP) layer. Other functional splits are also possible. Those skilled in the art are expected to be familiar with the OSI model and the functions within each layer.

[0039] In an embodiment, the server or CU can generate a virtual network through which the server communicates with radio nodes. Typically, virtual networking can involve the process of combining hardware and software network resources and functions into a single software-based management entity (virtual network). Such a virtual network can provide flexible distribution of operations between the server and the radio head / node. In practice, any digital signal processing task can be performed in the CU or DU, and the boundaries of responsibility transferred between the CU and DU can be selected depending on the implementation.

[0040] Some other potential technological advancements to utilize are Software-Defined Networking (SDN), big data, and all-IP, to name just a few non-limiting examples. For instance, network slicing can take the form of a virtual network architecture that uses the same principles behind Software-Defined Networking (SDN) and Network Functions Virtualization (NFV) in a fixed network. SDN and NFV can provide greater network flexibility by allowing traditional network architectures to be divided into virtual elements that can be linked (also via software). Network slicing allows the creation of multiple virtual networks on top of a shared physical infrastructure. These virtual networks can then be customized to meet the specific needs of applications, services, devices, customers, or operators.

[0041] Multiple gNBs (access points / nodes), each comprising a CU and one or more DUs, can connect to each other via the Xn interface, on which gNBs can negotiate. gNBs can also connect to the 5G core network (5GC) via the Next Generation (NG) interface, which can be the 5G equivalent of the LTE core network. This 5G CU-DU split architecture can be implemented using a cloud / server architecture, with the higher-level CU residing in the cloud and the DU closer to or including the actual radio and antenna units. Similar ongoing initiatives exist for LTE / LTE-A / eLTE. When eLTE and 5G will use a similar architecture in the same cloud hardware (HW), the next step could be to combine software (SW) to allow a common SW to control both the radio access network / technology (RAN / RAT). This could allow new ways to control the radio resources of both RANs. Furthermore, configurations can exist where the entire protocol stack is controlled by the same HW as the CU and processed by the same radio units as the CU.

[0042] It should also be understood that the workload allocation between core network operations and base station operations may differ from LTE, or even not exist at all. Other technological advancements that may be used include big data and all-IP, which could change how networks are built and managed. 5G (or New Radio, NR) networks are designed to support multiple hierarchical structures, where MEC servers can be placed between the core and base stations or nodeBs (gNBs). It should be understood that MEC can also be applied to 4G networks.

[0043] 5G can also leverage satellite communications to enhance or supplement 5G service coverage, for example, by providing backhaul. Possible use cases include providing service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or for passengers on transportation, or ensuring the availability of critical communications and future rail / sea / air communications. Satellite communications can utilize geostationary Earth orbit (GEO) satellite systems, but can also utilize low Earth orbit (LEO) satellite systems, particularly mega-constellations (systems deploying hundreds of (nanometer) satellites). Each satellite in a mega-constellation can cover a network entity of several supporting satellites that create a terrestrial cell. Terrestrial cells can be created via ground-based relay nodes or by gNBs located on the ground or in satellites.

[0044] The embodiments can also be applied to narrowband (NB) Internet of Things (IoT) systems, which enable various devices and services to connect using cellular telecommunications bands. NB-IoT is a narrowband radio technology designed for the Internet of Things (IoT) and is one of the technologies standardized by the 3rd Generation Partnership Project (3GPP). Other 3GPP IoT technologies suitable for implementing these embodiments include Machine-Type Communication (MTC) and eMTC (enhanced Machine-Type Communication). NB-IoT has a particular focus on low cost, long battery life, and support for a large number of connected devices. NB-IoT technology can be deployed “in-band” in spectrum allocated to Long Term Evolution (LTE)—using resource blocks within a normal LTE carrier, or using LTE carriers to protect unused resource blocks within the band—or “standalone” in dedicated spectrum.

[0045] The embodiments can also be applied to device-to-device (D2D), machine-to-machine, and peer-to-peer (P2P) communications. The embodiments can also be applied to vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and infrastructure-to-vehicle (I2V), or generally to V2X or X2V communications.

[0046] Figure 1 illustrates an example of a communication system to which embodiments of the present invention can be applied. The system may include a control node 110 providing one or more cells (e.g., cell 100), and a control node 112 providing one or more other cells, such as cell 102. For example, each cell may be, for example, a macro cell, micro cell, femtocell, or picocell. From another perspective, a cell may define the coverage area or service area of ​​a corresponding access node. Control nodes 110 and 112 may be evolved B-nodes (eNBs) such as those in LTE and LTE-A, ng-eNBs such as those in eLTE, gNBs in 5G, or any other means capable of controlling radio communications and managing radio resources within a cellular cell. Control nodes 110 and 112 may be referred to as base stations, network nodes, or access nodes.

[0047] The system can be a cellular communication system consisting of a radio access network of access nodes, with each access node controlling one or more corresponding cells. Access node 110 can provide user equipment (UE) 120 (one or more UEs) with radio access to other networks such as the Internet. Radio access can include downlink (DL) communication from the control node to UE 120 and uplink (UL) communication from UE 120 to the control node.

[0048] Additionally, although not shown, one or more local access nodes may be arranged such that the cell provided by the local access node at least partially overlaps with the cell of access nodes 110 and / or 112. The local access node may provide radio access within a sub-cell. Examples of sub-cells may include microcells, picocells, and / or femtocells. Typically, sub-cells provide hotspots within macrocells. The operation of the local access node may be controlled by the access node providing the sub-cell within its control area. Generally, the control node of a small cell may also be referred to as a base station, network node, or access node.

[0049] Multiple UEs 120 and 122 can exist in the system. Each of them can be served by the same or different control nodes 110 and 112. UEs 120 and 122 can communicate with each other to establish a D2D communication interface between them.

[0050] The term "terminal device" or "UE" refers to any terminal device capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices may include, but are not limited to, mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, LEE (Laptop embedded equipment), LME (Laptop mounted equipment), USB dongles, smart devices, wireless customer premises equipment (CPE), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain environments), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. In the following description, the terms “terminal equipment”, “communication equipment”, “terminal”, “user equipment” and “UE” are used interchangeably.

[0051] In a communication network with multiple access nodes, these nodes can connect to each other via an interface. The LTE specification refers to this interface as the X2 interface. A similar interface can be provided between access points for IEEE 802.11 networks (i.e., wireless local area networks, WLAN, WiFi). The interface between an LTE access point and a 5G access point, or between two 5G access points, can be called Xn. Other communication methods may also be used between access nodes. Access nodes 110 and 112 can also connect to the core network 116 of the cellular communication system via another interface. The LTE specification defines this core network as an evolved packet core (EPC), which may include a mobility management entity (MME) and gateway nodes. The MME can handle terminal device mobility in a tracking area covering multiple cells and handle signaling connections between terminal devices and the core network. Gateway nodes can handle data routing within the core network and to / from terminal devices. The 5G specification defines the core network as a 5G core (5GC), which may include, for example, Access and Mobility Management Functions (AMF) and User Plane Functions / Gateways (UPF), to name a few. AMF can handle Non-Access Stratum (NAS) signaling termination, NAS encryption and integrity protection, registration management, connection management, mobility management, access authentication and authorization, and security context management. For example, a UPF node can support packet routing and forwarding, packet inspection, and QoS processing.

[0052] A new configuration of responsibilities for the CU and DU in the control plane has been envisioned. This configuration is disclosed in patent publication WO2023 / 222190. In this configuration, there are two separate Radio Resource Control (RRC) entities that establish the control plane for the UE: one RRC entity in the CU establishes the CU control plane (CU-CP), and one RRC entity in the DU establishes the local control plane (L-CP). The L-CP can handle the UE's "local" mobility functions, such as forwarding NAS messages to the CU-CP and performing intra-gNB mobility operations, and is assigned its own UE identifier, which may include RRC processing for the selected UE. This may include performing L-CP functions at the UE level or at the Data Radio Bearer or Packet Data Unit (DRB / PDU) session level. This allows some CU-CP tasks related to RRC (such as LTM) to be offloaded to the L-CP while maintaining overall connectivity control and RRC termination at the CU-CP. The L-CP can be completely transparent to the core network. Additionally, this may require the RRC message and / or Packet Data Convergence Protocol (PDCP) layer to indicate the RRC entity to the UE so that the RRC message can be decrypted using the correct security key.

[0053] The CU-CP can synchronize with the L-CP after / during inter-gNB procedures (e.g., UE context release). The L-CP can coordinate / notify the CU-CP before or after mobility events, such as intra-CU handover. The CU-CP can obtain the latest UE RRC configuration from the L-CP when initiating an inter-gNB procedure; alternatively, the L-CP can synchronize with the CU-CP after each RRC procedure (e.g., Layer 3 handover).

[0054] However, using two different entities in a radio access network for the same or substantially similar processes (such as handover) at the same protocol layer can lead to confusing situations. Let's refer to... Figure 1B This illustrates a scenario where UE 120 is served by DU 210 and CU 200 and is moving towards DU 212 and DU 214, where DU 214 (and DU 216) are controlled by CU 202. Both DU 210 and CU 200 can receive measurement reports from UE 120: one processed by the DU for intra-CU handover and another processed by the CU for inter-CU handover. Therefore, both DU 210 and CU 200 can initiate concurrent Layer 3 handover preparation (to DU 212 and DU 214) and even issue handover commands to UE 120. As another example, the UE could receive two Conditional Handover (CHO) configurations: one from DU 210 and the other from CU 200. Using two CHO configurations can lead to unnecessary processing and power consumption in the UE and may result in unpredictable behavior within the UE.

[0055] For clarity, the following description uses the terms "intra-CU measurement" and "intra-CU handover." "Intra-CU measurement" includes measurements within a DU (cells within the same DU and CU) and measurements between DUs within a CU (cells under different DUs but within the same CU); "intra-CU handover" includes corresponding intra-DU handovers and inter-DU intra-CU handovers. Further, this specification uses the terms "inter-CU measurement" and "inter-CU handover," which respectively cover inter-DU and inter-CU measurements and handovers (cells under different DUs but belonging to different CUs). All intra-CU measurements can be routed to the L-CP, and intra-CU handovers can be handled by the L-CP. All inter-CU measurements can be routed to the CU-CP, and inter-CU handovers can be handled by the CU-CP. The terms DU and L-CP are used interchangeably. Similarly, in the context of this specification, the terms CU and CU-CP are used interchangeably because this specification focuses on control plane functions. Furthermore, in the following description, the described DU is controlled by the CU, and the DU communicates with the CU in conjunction with handover preparation for the UE.

[0056] Figure 2An embodiment for handling concurrent handover procedures in the aforementioned context is illustrated. This method can be performed by a device for a DU. The device can be a DU or be included within a DU. The device can manage the L-CP of the DU and communicate with the UE via the L-CP.

[0057] refer to Figure 2 The method includes: receiving a measurement report for the UE (box 220); determining, based on the received measurement report (box 222), to initiate an intra-cell handover procedure, wherein the initiation includes transmitting a message to the central unit of the control distribution unit for preventing concurrent execution of intra-cell handover procedures and inter-cell handover procedures for the user equipment; and, based on transmitting the message, performing an intra-cell handover procedure with the user equipment or canceling the initiated intra-cell handover procedure (box 224).

[0058] Figure 2 The process involves initiating an intra-CU handover procedure to establish coordination between the DU and CU. This coordination, in the form of messages, enables the DU to determine whether to perform an intra-CU handover procedure and avoids overlap between intra-CU and inter-CU handover procedures. The embodiments described below further illustrate how to reduce or prevent concurrent handover procedures.

[0059] Figure 3 Another embodiment for handling concurrent switching processes is shown. Figure 3 The method can be performed by a device used for the CU. This device can be the CU or be included within the CU. This device can manage the CU-CP and communicate with the UE via the CU-CP. Figure 3 Methods and Figure 2 The method is related, and the relationship is that the message sent by DU is... Figure 3 The same message received by the CU in the method.

[0060] refer to Figure 3 The method includes: receiving (box 300) a message from a distribution unit indicating that the distribution unit intends to perform an intra-unit handover procedure with a user equipment, the distribution unit being controlled by a central unit; receiving (box 302) a measurement report indicating an inter-unit handover procedure for the user equipment; and, based on the timing of the message and the measurement report (determined in box 304), performing (box 306) an inter-unit handover procedure based on the received measurement report and sending a second message to the distribution unit, the second message being used to prevent concurrent execution of intra-unit handover procedures and inter-unit handover procedures for the user equipment, or to determine that the inter-unit handover procedure will not be executed in order to allow the intra-unit handover procedure indicated by the message to be executed.

[0061] Figure 3 The embodiments provide with Figure 2The same advantages as the previous implementation are reduced or even eliminated concurrent handover processes for the UE at the CU and DU. This is achieved through coordination between the CU and DU in the form of (multiple) messages.

[0062] exist Figure 2 and Figure 3 In one embodiment, a measurement report for the UE is received. The measurement report may be received from the UE, for example, in the form of a neighboring cell measurement report. In another embodiment, the measurement report is based on the UE's location, and as is known in the art, the UE may be measured by the UE itself or by an anchor node near the UE that is capable of exchanging location signals with the UE. In such a case, the measurement report for the UE may be received from such an anchor node.

[0063] In one embodiment, the handover procedure is initiated based on a criterion other than receiving a measurement report. For example, the handover procedure may be initiated based on knowledge of the network layout. When a UE enters a cell, a specific set of neighboring cells may be prepared by default for the UE's handover. This set of neighboring cells may include cells within the same CU and / or cells within multiple CUs. The set of cells prepared may also change, for example, depending on the source cell from which the UE enters the cell. Therefore, in some cases only cells within the same CU may be prepared, while in other cases, the set of cells prepared may also include cells(s) controlled by another CU.

[0064] The following is for reference. Figures 4A to 5B A more detailed description Figure 2 and Figure 3 Examples of the method. Figure 4A and Figure 4B An embodiment is described in which a network node (DU or CU), upon determining that it needs to initiate a handover procedure for a UE, notifies another network node (DU or CU) of the initiation and then proceeds with the initiation. The other network node receiving the notification can disable the initiation of multiple handover procedures for the UE based on the receipt of the notification, thereby preventing concurrent handover procedures for the UE. In other words, the network node that determines to initiate a handover procedure and sends the message can perform the handover procedure without receiving a response to that message from another network node.

[0065] refer to Figure 4AThe CU can configure a measurement configuration for the UE, which is used to perform neighbor cell measurements for handover purposes. This measurement configuration can be an RRC configuration. The measurement configuration can instruct the UE how to report measurements. For example, the measurement configuration can instruct intra-CU measurements to be reported to the DU / L-CP, while inter-CU measurements are reported to the CU / CU-CP. The measurement configuration can include intra-CU measurement configurations and inter-CU measurement configurations. Intra-CU measurement configurations can, for example, instruct the UE to measure the cells of (multiple) DUs(s) of the CU for intra-CU handover purposes. Inter-CU measurement configurations can, for example, instruct the UE to measure the cells of (multiple) other CUs(s) for inter-CU handover purposes. The measurement configurations(s) can also instruct the timing of the corresponding measurement reports(s). The measurement configurations can also instruct any other measurement parameters. In step 400, the measurement configuration is sent from CU 200 to UE 120.

[0066] In box 402, UE 120 performs inter-CU measurements and intra-CU measurements by measuring the corresponding neighboring cells. Due to different reporting intervals configured in the measurement configuration, or due to other factors, UE 120 may report intra-CU measurements and inter-CU measurements at different times. Figure 4A In this embodiment, the UE reports intra-CU measurements to DU 210 in step 404, these measurements indicating the need to initiate an intra-CU handover procedure. Upon determining in step 406 that an intra-CU handover procedure needs to be initiated, DU 210 sends the aforementioned message indicating the initiation to CU 200 (step 408). The DU can begin handover preparation in step 410 without waiting for any response from CU 200. In other words, DU 210 can begin the handover procedure and related handover preparation without CU 200 confirmation. The CU can still at least confirm that it has received the message. Depending on the handover type, the handover preparation performed in step 410 may differ. This handover preparation may include sending UE context parameters to at least the neighboring DU(s) 212(s) in step 410.

[0067] When a notification is received in step 408, CU 200 can disable the handover initiation of UE 120. Therefore, when a measurement report including inter-CU measurements is received from UE 120 in step 412, even if the measurement indicates that inter-CU handover is required, CU 200 can omit the initiation of the handover process of UE 120 (box 414).

[0068] Figure 4B This demonstrates the process where the CU initiates the handover for the UE before the DU 210, therefore... Figure 4A The situation is reversed compared to the previous embodiment. (See reference...) Figure 4BWhen a measurement report is received in step 412, including inter-CU measurements indicating the need for inter-CU handover, the CU can determine to initiate an inter-CU handover procedure (block 420). Upon determining to initiate the inter-CU handover procedure in 420, CU 200 sends a message indicating the initiation to DU 210 (step 422), which may be similar to the message sent in step 408. The CU can then begin handover preparation with its neighboring CU 202 in step 424 without waiting for any response from DU 210. Figure 4A The process is similar; CU 200 can begin the handover process and related handover preparations without DU 210 confirmation. Depending on the handover type, the handover preparations performed in step 424 may differ. These handover preparations may include sending UE context parameters to at least the neighboring CU(s) 202(s) in step 424.

[0069] When a notification is received in step 422, DU 210 can disable the handover initiation of UE 120. Therefore, when a measurement report including intra-CU measurements is received from UE 120 in step 404, even if the measurement indicates that intra-CU handover is required, DU 210 can omit the initiation of the handover process for UE 120 (box 426).

[0070] exist Figure 4A and 4B In both embodiments, UE 120's handover preparation can be re-enabled after a specific event. This event could be an indication from a network node with an active handover process that the handover process has been released or that handover has been executed. Therefore, it can be executed again whenever the UE returns to the cell. Figure 4A or Figure 4B The process.

[0071] according to Figure 4B In the embodiment, the CU can also execute Figure 2 The process differs in that the handover process considered is an inter-CU handover process, and messages are transmitted from the CU to the DU and other DU(s) controlled by the CU. Therefore, Figure 2 The process can be adjusted to the following form: the CU receives a measurement report from the UE; based on the received measurement report, it determines to initiate an inter-CU handover process, wherein initiation includes sending a message to each distributed unit controlled by the CU, the message being used to prevent concurrent execution of intra-CU handover processes and inter-CU handover processes for the user equipment; and based on sending the message, performing an inter-CU handover process with the user equipment. According to this embodiment, the DU can receive a message from the CU, the message being used to prevent concurrent execution of intra-CU handover processes and inter-CU handover processes, and cancel / disable intra-CU handover processes(multiple) of UE 120.

[0072] Figure 4A and Figure 4B The implementation defines the handover preparation priority based on which type of measurement report is transmitted first and which network node (DU or CU) serving the UE initiates the handover procedure first. Therefore, from the CU's perspective, the timing of a message before the measurement report timing (step 412) (step 408) causes the handover procedure initiation in CU 200 to be disabled. On the other hand, the timing of a message after the measurement report timing (step 412) (step 408) causes the handover procedure to be initiated at CU 200.

[0073] Figure 5A and Figure 5B The diagram illustrates the process by which CU 200 controls the initiation of a handover procedure at (multiple) DUs 210, 212 controlled by CU 200. In these embodiments, (multiple) DUs 210, 212 must wait for approval from CU 200 before initiating the handover procedure. In other words, the DUs may wait for CU confirmation after transmitting a message, and execute the intra-cell handover procedure when it is determined that the confirmation indicates that the intra-cell handover procedure is approved. In this context, execution may mean initiating handover preparation for the UE. On the other hand, the DUs may cancel the intra-cell handover procedure when it is determined that the confirmation indicates that the CU rejects the intra-CU handover procedure.

[0074] exist Figure 5A and Figure 5B In, with Figure 4A and Figure 4B The same reference numerals in the figures indicate the same or substantially similar actions.

[0075] refer to Figure 5A Upon receiving a measurement report including intra-CU measurements (measurement data) in step 404, DU 210 can determine to initiate a handover procedure for UE 120 and therefore request handover preparation from CU 200 in step 500. Therefore, the message sent in step 500 may differ from the message sent in step 408, as this message is a request for a response from CU 200. Thus, DU can wait for this response before starting handover preparation. In this case, assuming there is no active handover procedure for UE 120 at CU 200, CU 200 can approve the request and send a corresponding confirmation message to DU 210 in step 502. DU can only continue intra-CU handover preparation in step 410 upon receiving this approval. Meanwhile, CU 200 may have disabled inter-CU handover procedures for UE 120. This means that if CU 200 receives a measurement report in step 412 indicating the need for inter-CU handover, CU 200 can omit handover preparation (414).

[0076] exist Figure 5BIn this embodiment, the timing of the measurement reports and the associated handover procedure initiation are in reverse order. Therefore, CU 200 can receive a measurement report including inter-CU measurements in 412, and thus trigger inter-CU handover preparation in 420. A subsequent measurement report including intra-CU measurements (404) can also trigger handover initiation in DU 210 and request sending in step 500. However, since CU 200 already has an active handover procedure for UE 120, the CU can reject the request and send a rejection (negative acknowledgment, NACK) in 504. Therefore, the DU can cancel the intra-CU handover procedure for UE 120 (426).

[0077] In summary, if the CU receives a measurement report including inter-CU measurements before instructing the DU to perform a handover procedure, the CU can perform the inter-CU handover procedure based on the received measurement report. Therefore, the CU can send a message including a handover procedure initiation instruction to (multiple) DUs, thereby preventing (multiple) DUs from initiating concurrent intra-cell handover procedures. This can also be applied to... Figure 5A and Figure 5B This embodiment reduces the need for DU 210 to unnecessarily request intra-CU handover preparation. If the CU receives the message before a measurement report including inter-CU measurements, the CU can determine not to perform the inter-CU handover procedure based on the received measurement report. In this embodiment, the CU can respond to the request from the DU with an acknowledgment indicating that the intra-CU handover procedure has been approved.

[0078] In one embodiment, UE 120 is configured to associate a measurement report with a timestamp and include the timestamp in a message. The timestamp indicates the moment the measurement was performed. Timestamps can be added to both measurement reports 412 and 404 separately. DU can pass this timestamp to the request sent in 500. If CU 200 receives measurement report 412 and message 500 substantially simultaneously, or at least before an inter-CU handover procedure has been initiated when both are received, and the inter-CU measurement indicates a need for an inter-CU handover, the CU can compare the timestamp of the received inter-CU measurement with the timestamp in the request received in 500 and determine which handover procedure to initiate based on the comparison. For example, the CU may prioritize the handover procedure based on the most recent measurement and thus initiate a handover procedure associated with the timestamp indicating the later moment. If request 500 indicates a later moment for the measurement within the CU, the procedure can follow... Figure 5A If the request indicates an earlier measurement within the CU, the procedure can be followed. Figure 5B .

[0079] In one embodiment, the above procedures can be applied to each type of handover. This means that these procedures are performed within each handover type, such as a Conditional Handover (CHO) procedure, a Layer 3 handover procedure, or a Layer 1 / Layer 2 Triggered Mobility (LTM) procedure. In other words, the intra-CU handover procedure and the inter-CU handover procedure in each embodiment can be the same type of handover. Therefore, concurrent Layer 3 intra-CU handover procedures and CHO inter-CU handover procedures can be allowed. In another embodiment, according to any of the embodiments described herein, concurrent handover procedures of the same handover type can be allowed, while concurrent handovers of different types can be prevented.

[0080] Preventing concurrent handover processes on the network side simplifies the process at the UE because it reduces the number of handover procedures the UE needs to consider. Alternatively, the aforementioned problem can be solved on the UE side. In other words, concurrent intra-CU and inter-CU handover processes can be allowed from the CU and DU. Figure 6 An example of the UE process in this scenario is shown. (Reference) Figure 6 The methods performed by the UE include: receiving intra-centralized unit handover configuration from a distributed unit controlled by a centralized unit (box 600); receiving inter-centralized unit handover configuration from a centralized unit (box 602); and performing a handover based on a determined criterion (604), according to only one of the intra-centralized unit handover configuration and the inter-centralized unit handover configuration (box 606 or 608).

[0081] In this embodiment, the UE receives a radio resource control configuration message indicating guidelines from the central unit.

[0082] In one embodiment, the UE enables intra-CU handover configuration and disables inter-CU handover configuration. Therefore, the determined criteria prioritize intra-CU handover configuration over inter-CU handover configuration. In another embodiment, the UE enables inter-CU handover configuration and disables intra-CU handover configuration.

[0083] Figures 7 to 8B Examples of various guidelines and configurations for handling concurrent handover processes at UE 120 are shown. Figure 7 An embodiment of CHO is shown, where intra-CU handover and inter-CU handover have separate execution conditions. Therefore, the criterion in 604 could be that one of the execution conditions becomes satisfied, and the corresponding handover will be executed in 606 or 608. Furthermore, the CU can determine which of the intra-CU handover and inter-CU handover should be prioritized by configuring a condition modification for one of the execution conditions.

[0084] refer to Figure 7The method performed by the UE may include: receiving (702) a handover configuration within a central unit from a distribution unit, the distribution unit being controlled by a central unit; receiving (704) a handover configuration between central units from a central unit; receiving (700) a configuration from a central unit for modifying the execution conditions of one of the handover configurations within the central unit and between the central units; changing at least one parameter of the execution conditions of one of the handover configurations within the central unit and between the central units based on the configuration for modifying the conditions; and after the change, performing (708) a handover of any handover configuration in which the corresponding execution conditions of the handover configuration within the central unit and the handover between the central units are satisfied.

[0085] The method may also include steps 400, 402, 404, and 412; however, it should be noted that this embodiment can, in principle, be performed without measurement reporting. For example, when a UE enters a cell, multiple neighboring cells can be prepared for the UE's handover without any measurements being performed. The network can utilize, for example, knowledge of network layout and cell coverage areas.

[0086] In one embodiment, step 700 is part of step 400. In other words, the configuration for modifying the execution conditions can be included in the measurement configuration. In another embodiment, steps 700 and 400 are implemented via different messages, such as different RRC messages.

[0087] In one embodiment, in 3GPP terminology, the modified handover execution condition is the A3 event, which is the situation where a neighboring cell becomes a cell with a higher received signal strength by an offset, and this modification can be an offset parameter. The A3 event can be associated with a trigger time-to-trigger (TTT) parameter that controls handover execution such that the A3 event must be met within the TTT duration to trigger handover execution. TTT is another embodiment of the parameter that can be modified via step 700.

[0088] This change can be applied only to one of the intra-CU and inter-CU handover configurations, and as described above, it is applied conditionally. The condition can be the existence of other handover configurations. In other words, the modification can be disabled when the UE has only one handover configuration and enabled when multiple concurrent handover configurations exist.

[0089] This modification can lead to the UE preferring one or the other of intra-CU handover and inter-CU handover, depending on the modification. For example, if the UE is configured to increase the offset and / or increase the TTT parameter of the intra-CU handover configuration, it results in a preference for inter-CU handover because neighboring intra-CU cells should provide signal strength greater than the default offset and / or provide signal strength higher than the (modified) offset for a longer duration. Similarly, if the UE is configured to decrease the offset and / or decrease the TTT parameter of the intra-CU handover configuration, it results in a preference for intra-CU handover because neighboring intra-CU cells should provide signal strength less than the default offset and / or provide signal strength higher than the (modified) offset for a shorter duration. The same principle naturally applies if the condition modification targets the inter-CU handover execution conditions.

[0090] In one embodiment, the configuration for condition modification is received as part of the measurement reporting configuration (step 400), and this configuration disables the transmission of measurement reports. In 3GPP terminology, the measurement configuration can define a new ReportConfig that, when triggered, does not generate a measurement report but instead implements modifications to the execution conditions.

[0091] In this embodiment, both the intra-CU switching configuration and the inter-CU switching configuration can be CHO configurations.

[0092] Figure 8A and Figure 8B Involving as Figure 6 One modified embodiment of the method. Typically, this embodiment may include: sending a first measurement report to a distributed unit controlled by a centralized unit; receiving a first handover configuration in at least a first message, the first handover configuration being used for handover between the distributed unit and another distributed unit controlled by the centralized unit; sending a second measurement report to the centralized unit; receiving a second handover configuration in at least a second message, the second handover configuration being used for handover from the centralized unit to another centralized unit; determining a criterion for prioritizing the handover configurations, and based on the criterion, disabling one of the first and second handover configurations and enabling the other of the first and second handover configurations.

[0093] This criterion can specify the priority order between inter-CU handover and intra-CU handover through various factors, as described below. In an embodiment, the determined criterion ensures that a handover configuration received earlier should be executed. In an embodiment, the determined criterion prioritizes handover configurations for unconditional (Layer 3) handover over handover configurations for conditional handover. In an embodiment, the determined criterion prioritizes inter-CU handover configurations over intra-CU handover configurations. In an embodiment, this criterion is based on radio measurements performed by the user equipment.

[0094] refer to Figure 8A The CU can determine criteria (or multiple criteria) in block 800 and transmit these criteria to the UE, for example, via an RRC message. Steps 400, 402, 404, and 412 can be performed as described above. Based on the measurement report received in 404, DU 210 can determine to initiate an intra-CU handover and accordingly perform handover preparation with the neighboring DU(multiple) DU(212) and UE 120 in step 802. Therefore, the UE receives the intra-CU handover configuration from DU 210. Similarly, based on the measurement report received in 412, CU 200 can determine to initiate an inter-CU handover and accordingly perform handover preparation with the neighboring CU(202) and UE 120 in step 804. Therefore, the UE receives the inter-CU handover configuration from CU 200. In this embodiment, coordination between the CU and DU can be omitted.

[0095] Upon receiving a second handover configuration and determining that there are multiple concurrent handover (HO) configurations, UE 120 can use the received criteria in 806 to determine which of the handover configurations to use for handover. In an embodiment, the UE uses the following table, which may be fixed or indicated in block 800.

[0096]

[0097] In another embodiment, a different priority table may be used.

[0098] According to the table above, if both handover configurations are Layer 3 configurations, the UE can first follow the handover configuration commanded by the corresponding network node. In another embodiment, the action can be to override one of the concurrent handover configurations to prioritize Layer 3 handover within or between CUs. In cases 2 and 3, Layer 3 can take precedence over CHO.

[0099] Regarding scenario 4, some embodiments are described below. In one embodiment, scenario 4 describes an inter-CU Choo that will reject intra-CU handover. Therefore, if the UE already has an inter-CU Choo configuration and it receives an intra-CU Choo configuration, it will ignore the intra-CU Choo configuration. If the UE already has an intra-CU Choo configuration and it receives an inter-CU Choo configuration, it will discard the intra-CU Choo configuration and adopt the inter-CU Choo configuration. In another embodiment, scenario 4 describes an intra-CU Choo that will reject inter-CU handover. Therefore, if the UE already has an intra-CU Choo configuration and it receives an inter-CU Choo configuration, it will ignore the inter-CU Choo configuration. If the UE already has an inter-CU Choo configuration and it receives an intra-CU Choo configuration, it will discard the inter-CU Choo configuration and adopt the intra-CU Choo configuration.

[0100] In another embodiment, the priority of CHO configuration depends on radio measurements. The UE can maintain two concurrently enabled CHO configurations for the duration of the radio measurements. The radio measurements can be signal strength measurements, and the CHO configuration associated with the stronger signal strength measured by the UE should take precedence over the CHO configuration associated with the weaker signal strength. The signal strength measurement considered can be neighboring cell signal measurements. The UE can evaluate which set of one or more cells provides greater (collective) signal strength based on the radio measurements: the set of cells for intra-CU CHO measurements and the set of cells for inter-CU CHO measurements.

[0101] In this embodiment, the criteria include only a subset of the options in the table. As mentioned above, some options can be replaced by others.

[0102] When selecting a handover configuration, the UE can notify the network node which handover configuration has been selected. Figure 8A In this embodiment, the UE selects an inter-CU handover configuration, and therefore sends a message indicating this selection to CU 200 in 808. This message may include information elements indicating a concurrent intra-CU handover configuration with DU 210. Upon receiving this notification, CU 200 may notify DU 210 in 810 that the intra-CU handover configuration has been rejected, so DU 210 may release the intra-CU handover configuration together with the UE and(multiple) DU 212 in 812. This message may be an RRCReconfigurationComplete message. Alternatively, the UE may directly notify DU 210 that the intra-CU handover configuration should be released, for example, in a separate RRC message addressed to the L-CP. Therefore, DU will execute 812. In 814, UE 120 performs a handover and performs random access with CU 202 in the CU-CP.

[0103] exist Figure 8B In this embodiment, the UE selects intra-CU handover in 806. Therefore, the UE can transmit a message to CU 200 in 820 indicating that the intra-CU handover configuration has been selected and the inter-CU handover configuration should be released. This message can be an RRCReconfigurationComplete message. In response to receiving this message in 820, the CU can release the inter-CU handover configuration with UE 120 and CU 202. In 824, the UE performs intra-CU handover with DU 212 in the L-CP.

[0104] like Figure 9As shown, one embodiment provides an apparatus 10 including a control circuitry (CTRL) 12 (e.g., at least one processor) and at least one memory 14 storing instructions that, when executed by the at least one processor, cause the apparatus to perform at least one of the processes described above. For example, at least one memory and computer program code (software) together with at least one processor are configured to cause the apparatus to perform... Figure 6 The process or any of the above embodiments of the process. The memory can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The memory may include a database for storing data.

[0105] In one embodiment, device 10 may include terminal devices 120, 122 of a communication system, such as a user terminal (UT), computer (PC), laptop computer, tablet computer, cellular phone, mobile phone, communicator, smartphone, handheld computer, mobile transportation device (e.g., automobile), home appliance, or any other communication device, generally referred to herein as UE. Alternatively, the device may be included in such a terminal device. Furthermore, the device may be or include a module providing connectivity (to be attached to the UE), such as a plug-in unit, a "USB dongle," or any other type of unit. This unit may be installed inside the UE, or attached to the UE via a connector, or even wirelessly attached to the UE.

[0106] In this embodiment, device 10 is UE 120, or is included in UE 120. The device can perform... Figure 6 Some functions of the above process or any embodiment thereof.

[0107] The device may also include a radio interface (TRX) 16, which includes hardware and / or software for establishing a communication connection according to one or more communication protocols. For example, the TRX can provide the device with communication capabilities for accessing a radio access network.

[0108] The device may also include a user interface 18, which may include, for example, at least one keypad, microphone, touch display, monitor, speaker, etc. A user can use the user interface to control the device.

[0109] Control circuit 12 may include a handover configuration circuit 20 for configuring the handover process in the UE. The handover configuration circuit may receive multiple handover configurations, one from the CU and another from a DU controlled by the CU. Control circuit 12 may also include a handover (HO) configuration (CONF) selection circuit 22 for selecting one of the provided handover configurations. Circuit 22 may perform a hard decision based on the table above, in which case only one of the received configurations should be active or undergo handover preparation at UE 120. The circuit may also perform a soft decision, in which case two or all handover configurations may undergo handover preparation at UE 150, and may monitor the corresponding handover execution conditions for two or all prepared handover configurations. Whenever circuit 22 detects a handover execution condition, the circuit may trigger handover execution, for example by issuing a handover execution command to handover execution circuit 24. For example, circuit 24 may be configured to perform random access to the selected cell. Control circuit 12 may include associated circuitry for performing functions according to any embodiment.

[0110] like Figure 10 As shown, one embodiment provides an apparatus 50 including a control circuit (CTRL) 52 (e.g., at least one processor) and at least one memory 54 storing instructions that, when executed by the at least one processor, cause the apparatus to perform at least one of the processes described above for the DU or CU, for example... Figure 2 or Figure 3 The process or any embodiment of that process. For example, at least one memory and computer program code (software), together with at least one processor, are configured to cause the device to perform any of the processes described above. The memory can be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The memory may include a database for storing data. It should be understood that... Figure 10 The devices are quite versatile, and the specific implementations of the DU and CU can vary depending on the embodiments and designs of the DU and CU, respectively. For example, for Figure 4A and Figure 4B In the embodiments described, the designs of DU and CU may be quite similar in terms of features. Figure 5A and Figure 5B In some embodiments, these designs differ because the CU is the master device that approves the handover initiation of DU 210, 212.

[0111] In one embodiment, device 50 may be a network node, or be included in a network node, such as in DU210 or CU 200. In one embodiment, the device is network node 110, or is included in network node 110. The device may be able to perform some of the functions described above, such as... Figure 2 and / or Figure 3 The steps.

[0112] The device may also include a communication interface (TRX) 56, which includes hardware and / or software for establishing communication connections according to one or more communication protocols. For example, the TRX may provide the device with communication capabilities with at least one user equipment. The device may also include a network interface 58, which is configured to provide the device with communication capabilities within a radio access network and / or with a core network. The network interface may support protocols for at least some of the following interfaces, such as those in the 5G specification or its equivalents in the 6G specification: the F1 interface between the DU and CU, the Xn interface between the two CUs, and the NG interface between the DU / CU and the core network.

[0113] Control circuitry 52 may include handover configuration circuitry 60, which is configured to process measurement reports received from (multiple) UEs and evaluate the handover requirements of (multiple) UEs. As described above, handover configuration may be initiated based on another criterion or other criteria instead of measurement reports. When determining to initiate a handover process for a UE, circuitry 60 may transmit notifications to other (multiple) network nodes, such as DUs or CUs. According to an embodiment, circuitry 60 may simultaneously trigger handover notification circuitry 64 to transmit notifications and trigger handover preparation circuitry 62 to perform handover preparations for the UE, such as configuring (multiple) candidate target cells for handover. Figure 4A and Figure 4B The embodiment is such an embodiment. Figure 5A and Figure 5B In one embodiment, the switching configuration circuit 62 may trigger only the switching notification circuit 64, which is configured to wait for confirmation from the CU, before the switching preparation circuit 64 triggers the switching preparation circuit 62.

[0114] In one embodiment, a CU-DU (centralized unit-distributed unit) architecture is implemented. In this case, device 50 may be included in a centralized unit (e.g., control unit, edge cloud server, server) operatively coupled (e.g., via a wireless or wired network) to a distributed unit (e.g., a remote radio head / node). That is, the centralized unit (e.g., the edge cloud server) and the radio nodes may be independent devices communicating with each other via a radio path or wired connection. Alternatively, they may reside in the same entity communicating via a wired connection, etc. The edge cloud or edge cloud server may serve multiple radio nodes or a radio access network. In one embodiment, at least some of the processes in the described process may be performed by the centralized unit. In another embodiment, the device may alternatively be included in a distributed unit, and at least some of the processes in the described process may be performed by the distributed unit. In one embodiment, the execution of at least some functions of device 50 may be shared by two physically separate devices (DU and CU) forming an operational entity. Therefore, the device can be considered to depict an operational entity comprising one or more physically separate devices for performing at least some of the processes in the described process. In one embodiment, the device controls the execution of these processes regardless of its location or where these processes / functions are performed.

[0115] In embodiments, an apparatus for executing at least some of the described embodiments includes at least one processor and at least one memory including computer program code, wherein the at least one memory and the computer program code are configured, together with the at least one processor, to cause the apparatus to perform the functions according to any of the described embodiments. According to one aspect, when the at least one processor executes the computer program code, the computer program code causes the apparatus to perform the functions according to any of the described embodiments. According to another embodiment, an apparatus for executing at least some embodiments includes at least one processor and at least one memory including computer program code, wherein the at least one processor and the computer program code perform at least some of the functions according to any of the described embodiments. Thus, at least one processor, memory, and computer program code form a processing component for executing at least some of the described embodiments. According to yet another embodiment, an apparatus for executing at least some embodiments includes circuitry including at least one processor and at least one memory including computer program code. When activated, the circuitry causes the apparatus to perform at least some of the functions according to any of the described embodiments.

[0116] As used herein, the term "circuit" refers to all of the following: (a) a hardware circuit implementation, such as an implementation employing only analog and / or digital circuitry; and (b) a combination of circuitry and software (and / or firmware), such as (as the case may be): (i) a combination of (multiple) processors, or (ii) a portion of (multiple) processors / software, including (multiple) digital signal processors, software, and (multiple) memories working together to enable the device to perform various functions; and (c) circuitry requiring software or firmware to function, such as (multiple) microprocessors or a portion of (multiple) microprocessors, even if the software or firmware is not physically present. This definition of "circuit" applies to all uses of the term in this application. As a further example, as used herein, the term "circuit" also covers an implementation of only a processor (or multiple processors) or a portion of a processor and its accompanying software and / or firmware. For example, and where applicable to a particular element, the term "circuit" also covers a baseband integrated circuit or application processor integrated circuit for a mobile phone, or a similar integrated circuit in a server, cellular network device, or another network device.

[0117] In one embodiment, at least some of the processes described may be performed by means including corresponding components for performing at least some of the processes described. Some example components for performing these processes may include at least one of the following: a detector, a processor (including dual-core and multi-core processors), a digital signal processor, a controller, a receiver, a transmitter, an encoder, a decoder, a memory, RAM, ROM, software, firmware, a display, a user interface, display circuitry, user interface circuitry, user interface software, display software, circuitry, an antenna, antenna circuitry, and circuitry.

[0118] As used herein, the term nontransient refers to a limitation on the medium itself (i.e., tangible, not signaling), rather than a limitation on the persistence of data storage (e.g., RAM vs. ROM).

[0119] As used herein, the term "component" should be interpreted in the singular form, meaning a single element, or in the plural form, meaning a combination of single elements. Therefore, the term "component for [performing A, B, C]" should be interpreted to cover an apparatus in which there is only one component for performing A, B, and C, or components for performing A, B, and C are respectively present, or components for performing A, B, and C are partially or completely overlapping. Furthermore, the terms "component for performing A, component for performing B, component for performing C" should be interpreted to cover an apparatus in which there is only one component for performing A, B, and C, or components for performing A, B, and C are respectively present, or components for performing A, B, and C are partially or completely overlapping.

[0120] According to a first aspect, an apparatus for a distributed unit is provided, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive a measurement report for a user equipment; determine, based on the received measurement report, to initiate an intra-unit handover process, wherein initiation includes sending a message to a centralized unit controlling the distributed unit, the message being used to prevent concurrent execution of intra-unit handover processes and inter-unit handover processes for the user equipment; and, based on sending the message, performing an intra-unit handover process with the user equipment, or canceling the initiated intra-unit handover process.

[0121] In one embodiment, the device is configured to perform a handover process within a central unit in the absence of a response to the message from the central unit.

[0122] In one embodiment, the device is configured to wait for confirmation from the central unit when sending the message, and to perform the intra-central unit handover procedure when it is determined that the confirmation indicates that the central unit approves the intra-central unit handover procedure.

[0123] In one embodiment, the device is configured to wait for confirmation from the central unit when sending the message, and to cancel the intra-central unit handover process when it is determined that the confirmation indicates that the central unit rejects the intra-central unit handover process.

[0124] In an embodiment, the device is further configured to receive a second message from a central unit, the second message being used to prevent concurrent intra-central unit switching processes and inter-central unit switching processes, and to cancel an intra-central unit switching process or another intra-central unit switching process.

[0125] In one embodiment, the device is also configured to associate a measurement report with a timestamp and include the timestamp in the message.

[0126] According to a first aspect, an apparatus for a central unit is provided, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive a message from a distributed unit controlled by the central unit, the message indicating that the distributed unit intends to perform an intra-central unit handover process with a user equipment; receive a measurement report for the user equipment, the measurement report indicating an inter-central unit handover process; and, based on timing of the message and the measurement report, perform the inter-central unit handover process based on the received measurement report and send a second message to the distributed unit, the second message being used to prevent concurrent execution of the intra-central unit handover process and the inter-central unit handover process for the user equipment, or to determine that the inter-central unit handover process is not performed, thereby allowing the intra-central unit handover process indicated by the message to be performed.

[0127] In an embodiment, if a measurement report is received before the message, the device is configured to perform a central unit handover process based on the received measurement report, wherein the second message is a response to a message received from the distributed unit, and wherein the second message indicates that the central unit refuses to perform a central unit handover process, the central unit handover process being indicated by a message received from the distributed unit.

[0128] In one embodiment, if a measurement report is received prior to the message, the device is configured to perform a handover process between centralized units based on the received measurement report, and wherein the second message is an indication to the distributed unit indicating that the centralized unit is performing a handover process for a user equipment, and the second message prevents the distributed unit from initiating a concurrent handover process within the centralized unit.

[0129] In one embodiment, if the message is received before the measurement report, the device is configured to determine, based on the received measurement report, not to perform a centralized unit switching process.

[0130] In one embodiment, the device is configured to send an acknowledgment indicating that the handover process within the central unit has been approved in response to the message.

[0131] In one embodiment, the message includes a timestamp indicating the timing of a second measurement report received by a distributed unit and triggering a handover process within a centralized unit, wherein the device is configured to compare the timestamp with the timing of a measurement report indicating a handover process between centralized units, and to determine, based on the comparison, whether to perform a handover process between centralized units.

[0132] In one embodiment, both the intra-unit handover process and the inter-unit handover process are the same type of handover process: conditional handover process, layer 3 handover process, or layer 1 / layer 2 triggered mobility.

[0133] According to a first aspect, a method is provided, comprising: receiving a measurement report for a user equipment by a distributed unit; determining, based on the received measurement report, to initiate an intra-unit handover process, wherein initiation includes sending a message to a centralized unit controlling the distributed unit, the message being used to prevent concurrent execution of intra-unit handover processes and inter-unit handover processes for the user equipment; and, based on sending the message, performing an intra-unit handover process with the user equipment by the distributed unit, or canceling the initiated intra-unit handover process.

[0134] In one embodiment, if there is no response to the message from the central unit, the distributed unit performs a handover procedure within the central unit.

[0135] In one embodiment, when sending the message, the distributed unit waits for confirmation from the centralized unit, and when it determines that the confirmation indicates that the centralized unit approves the intra-unit handover process, it executes the intra-unit handover process.

[0136] In one embodiment, when sending the message, the distribution unit waits for confirmation from the central unit, and cancels the handover process within the central unit when it determines that the confirmation indicates that the central unit rejects the handover process within the central unit.

[0137] In an embodiment, the method further includes receiving a second message from the central unit by the distributed unit, the second message being used to prevent concurrent intra-central unit switching processes and inter-central unit switching processes, and to cancel intra-central unit switching processes or switching processes within another central unit.

[0138] In one embodiment, the distribution unit associates the measurement report with a timestamp and includes the timestamp in the message.

[0139] According to a first aspect, a method is provided, comprising: a centralized unit receiving a message from a distributed unit controlled by the centralized unit, the message indicating that the distributed unit intends to perform an intra-unit handover process with a user equipment; the centralized unit receiving a measurement report for the user equipment, the measurement report indicating an inter-unit handover process; based on the timing of the message and the measurement report, the centralized unit performing the inter-unit handover process based on the received measurement report, and sending a second message to the distributed unit to prevent concurrent execution of the intra-unit handover process and the inter-unit handover process for the user equipment, or the centralized unit determining not to perform the inter-unit handover process to allow the intra-unit handover process indicated by the message to be performed.

[0140] In an embodiment, if a measurement report is received before the message, the central unit performs a central unit handover process based on the received measurement report, wherein the second message is a response to a message received from the distribution unit, and wherein the second message indicates that the central unit refuses to perform a central unit handover process, the central unit handover process being indicated by a message received from the distribution unit.

[0141] In one embodiment, if a measurement report is received before the message, the central unit performs an inter-central unit handover process based on the received measurement report, and the second message is an indication to the distributed unit indicating that the central unit is performing a handover process for the user equipment, and the second message prevents the distributed unit from initiating a concurrent intra-central unit handover process.

[0142] In one embodiment, if the message is received before the measurement report, the central unit determines not to perform the central unit switching process based on the received measurement report.

[0143] In one embodiment, the central unit responds to the message by sending an acknowledgment indicating that the handover process within the central unit has been approved.

[0144] In one embodiment, the message includes a timestamp indicating the timing of a second measurement report received by a distributed unit and triggering a handover process within a centralized unit, wherein the centralized unit compares the timestamp with the timing of a measurement report indicating a handover process between centralized units, and determines, based on the comparison, whether to perform a handover process between centralized units.

[0145] In one embodiment, both the intra-unit handover process and the inter-unit handover process are the same type of handover process: conditional handover process, layer 3 handover process, or layer 1 / layer 2 triggered mobility.

[0146] According to a first aspect, a computer program product is provided, embodied on a computer-readable distribution medium and including program instructions that, when executed by a device, cause the device to perform a method according to any of the embodiments described above in the first aspect.

[0147] According to a second aspect, an apparatus for a user equipment is provided, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive an intra-centralized unit handover configuration from a distributed unit controlled by a centralized unit; receive an inter-centralized unit handover configuration from the centralized unit; and perform a handover based on only one of the intra-centralized unit handover configuration and the inter-centralized unit handover configuration, according to a determined criterion.

[0148] In one embodiment, the device is configured to receive determined criteria in a radio resource control configuration message.

[0149] In an embodiment, the determined criteria dictate that a handover configuration received earlier than another should be executed.

[0150] In an embodiment, the determined criteria make a handover configuration for unconditional handover take precedence over a handover configuration for conditional handover.

[0151] In the embodiments, the determined criteria prioritize inter-centralized unit switching configurations over intra-centralized unit switching configurations.

[0152] In the embodiments, the determined criteria prioritize intra-centralized unit switching configurations over inter-centralized unit switching configurations.

[0153] In this embodiment, the handover configuration associated with a stronger signal strength measured by the user equipment should take precedence over the handover configuration associated with a weaker signal strength.

[0154] In one embodiment, the device is configured to send a configuration completion message for another of the intra-unit switching configuration and the inter-unit switching configuration, wherein the configuration completion message includes a notification that one of the switching configurations has been discarded.

[0155] According to a second aspect, a method is provided, comprising: receiving, by a user equipment, a handover configuration within a central unit from a distributed unit, the distributed unit being controlled by a central unit; receiving, by the user equipment, an inter-central unit handover configuration from the central unit; and, based on determined criteria, performing a handover according to one of the handover configurations within the central unit and the inter-central unit handover configuration.

[0156] In one embodiment, the user equipment receives the determined criteria in a radio resource control configuration message.

[0157] In an embodiment, the determined criteria dictate that a handover configuration received earlier should be executed.

[0158] In an embodiment, the determined criteria make a handover configuration for unconditional handover take precedence over a handover configuration for conditional handover.

[0159] In the embodiments, the determined criteria prioritize inter-centralized unit switching configurations over intra-centralized unit switching configurations.

[0160] In the embodiments, the determined criteria prioritize intra-centralized unit switching configurations over inter-centralized unit switching configurations.

[0161] In this embodiment, the handover configuration associated with a stronger signal strength measured by the user equipment should take precedence over the handover configuration associated with a weaker signal strength.

[0162] In one embodiment, the user equipment sends a configuration completion message for another of the intra-unit handover configuration and inter-unit handover configuration, wherein the configuration completion message includes a notification that the one of the handover configurations has been discarded.

[0163] According to a second aspect, a computer program product is provided, embodied on a computer-readable distribution medium and including program instructions that, when executed by a device, cause the device to perform a method according to any of the embodiments described above in the second aspect.

[0164] According to a third aspect, an apparatus for a user equipment is provided, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: receive an intra-unit switching configuration from a distributed unit, the distributed unit being controlled by a centralized unit; receive an inter-unit switching configuration from the centralized unit; receive a configuration from the centralized unit configuring an execution condition for modifying the execution condition of one of the intra-unit switching configuration and the inter-unit switching configuration; change at least one parameter of the execution condition of one of the intra-unit switching configuration and the inter-unit switching configuration based on the configuration for modifying the condition; and, after the change, perform a switch to execute any one of the switching configurations in which the corresponding execution condition in the intra-unit switching configuration and the intra-unit switching configuration becomes satisfied.

[0165] In one embodiment, the modification of the execution condition is based on the existence of multiple concurrent switching configurations at the user equipment.

[0166] In this embodiment, the modification of the execution conditions is enabled when multiple concurrent switching configurations exist at the user equipment, and disabled when only one switching configuration exists at the user equipment.

[0167] In one embodiment, the condition modification is affected by the measurement offset of neighboring cells.

[0168] In one embodiment, the condition modification is affected by the trigger time switching execution parameters.

[0169] In one embodiment, the configuration for condition modification is received as part of the measurement reporting configuration, wherein the configuration disables the sending of measurement reports.

[0170] In this embodiment, both the intra-unit switching configuration and the inter-unit switching configuration are conditional switching configurations.

[0171] According to a second aspect, a method is provided, comprising: receiving, by a user equipment, an intra-unit handover configuration from a distributed unit, the distributed unit being controlled by a centralized unit; receiving, by the user equipment, an inter-unit handover configuration from the centralized unit; receiving, by the user equipment, a configuration for modifying the execution conditions of one of the handover configurations, the intra-unit handover configuration and the inter-unit handover configuration; based on the configuration for modifying the conditions, changing at least one parameter of the execution condition of the one handover configuration, the intra-unit handover configuration and the inter-unit handover configuration; and after the change, performing a handover by the user equipment of any one of the handover configurations where the corresponding execution conditions of the intra-unit handover configuration and the inter-unit handover configuration are satisfied.

[0172] In one embodiment, the modification of the execution conditions is based on the existence of multiple concurrent switching configurations at the user equipment.

[0173] In this embodiment, the modification of the execution conditions is enabled when multiple concurrent switching configurations exist at the user equipment, and disabled when only one switching configuration exists at the user equipment.

[0174] In one embodiment, the condition modification is affected by the neighboring cell measurement offset.

[0175] In one embodiment, the condition modification is affected by the trigger time switching execution parameters.

[0176] In one embodiment, the configuration for condition modification is received as part of the measurement reporting configuration, wherein the configuration disables the sending of measurement reports.

[0177] In this embodiment, both the intra-unit switching configuration and the inter-unit switching configuration are conditional switching configurations.

[0178] According to this aspect, a computer program product is provided, embodied on a computer-readable distribution medium and including program instructions that, when executed by a device, cause the device to perform a method according to any of the embodiments described above in the second aspect.

[0179] The techniques and methods described herein can be implemented through various components. For example, these techniques can be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or combinations thereof. For hardware implementation, the embodiments may be implemented within one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or combinations thereof. For firmware or software, it may be implemented through modules (e.g., procedures, functions, etc.) of at least one chipset that perform the functions described herein. Software code may be stored in memory cells and executed by a processor. Memory cells may be implemented inside or outside the processor. In the latter case, as is known in the art, they may be communicatively coupled to the processor via various components. Furthermore, as those skilled in the art will understand, the components of the systems described herein may be rearranged and / or supplemented by additional components to facilitate the implementation of various aspects described with respect to these systems, and these components are not limited to the precise configurations illustrated in the given figures.

[0180] The described embodiments can also be performed as a computer process defined by a computer program or parts thereof. Embodiments of the described methods can be performed by executing at least one portion of a computer program including corresponding instructions. The computer program can be in source code form, object code form, or some intermediate form, and can be stored in some kind of carrier, which can be any entity or device capable of carrying the program. For example, the computer program can be stored on a computer or processor-readable computer program distribution medium. The computer program medium can be, for example, but not limited to, recording media, computer memory, read-only memory, electrical carrier signals, telecommunication signals, and software distribution packages. The computer program medium can be a non-transitory medium. The software coding used to perform the illustrated and described embodiments is entirely within the capabilities of those skilled in the art.

[0181] Although the invention has been described above with reference to examples in the accompanying drawings, it is apparent that the invention is not limited thereto, but can be modified in various ways within the scope of the appended claims. Therefore, all words and expressions should be interpreted broadly, and are intended to illustrate rather than limit the embodiments. It will be apparent to those skilled in the art that the inventive concept can be implemented in various ways as technology advances. Furthermore, it will be clear to those skilled in the art that the described embodiments can, but are not necessarily, combined with other embodiments in various ways.

Claims

1. An apparatus for a distribution unit, comprising: At least one processor; as well as At least one memory, the at least one memory storing instructions that, when executed by the at least one processor, cause the device to at least: For receiving measurement reports from user equipment; Based on the received measurement report, a handover process within a centralized unit is initiated, wherein initiation includes sending a message to the centralized unit controlling the distributed unit, the message being used to prevent concurrent handover processes within and between centralized units for the user equipment. as well as Based on sending the message, the user equipment can perform the intra-unit handover process or cancel the initiated intra-unit handover process.

2. The apparatus of claim 1, wherein the apparatus is configured to perform a handover process within the central unit in the absence of a response to the message from the central unit.

3. The apparatus of claim 1, wherein the apparatus is configured to: wait for confirmation from the central unit when sending the message, and execute the intra-central unit handover procedure when it is determined that the confirmation instructs the central unit to approve the intra-central unit handover procedure.

4. The apparatus of claim 1, wherein the apparatus is configured to wait for confirmation from the central unit when sending the message, and to cancel the intra-central unit handover process when it is determined that the confirmation indicates that the central unit rejects the intra-central unit handover process.

5. The apparatus according to any one of the preceding claims, further configured to receive a second message from the central unit, the second message being used to prevent the concurrent intra-central unit switching process and inter-central unit switching process, and to cancel the intra-central unit switching process or another intra-central unit switching process.

6. The apparatus according to any one of the preceding claims, wherein the apparatus is configured to associate the measurement report with a timestamp and include the timestamp in the message.

7. An apparatus for a centralized unit, comprising: At least one processor; as well as At least one memory, the at least one memory storing instructions that, when executed by the at least one processor, cause the device to at least: Receive a message from the distributed unit controlled by the centralized unit, the message indicating that the distributed unit intends to perform a handover process with the user equipment within the centralized unit; The user equipment receives a measurement report, which indicates the handover process between centralized units; Based on the timing of the message and the measurement report, a central unit handover process is executed based on the received measurement report, and a second message is sent to the distributed unit to prevent concurrent central unit handover processes and central unit handover processes of the user equipment, or to determine that the central unit handover process is not executed in order to allow the central unit handover process indicated by the message to be executed.

8. The apparatus of claim 7, wherein if the measurement report is received prior to the message, the apparatus is configured to perform the inter-centralized unit handover process based on the received measurement report, wherein the second message is a response to the message received from the distributed unit, and wherein the second message indicates that the centralized unit refuses to perform the intra-centralized unit handover process, the intra-centralized unit handover process being indicated by the message received from the distributed unit.

9. The apparatus of claim 7, wherein if the measurement report is received before the message, the apparatus is configured to perform the inter-centralized unit handover process based on the received measurement report, and wherein the second message is an indication to the distributed unit for indicating that the centralized unit is performing a handover process for the user equipment, and the second message prevents the distributed unit from initiating a concurrent intra-centralized unit handover process.

10. The apparatus of claim 7, wherein if the message is received before the measurement report, the apparatus is configured to determine, based on the received measurement report, not to perform the central unit switching process.

11. The apparatus of claim 10, wherein the apparatus is configured to, in response to the message, send an acknowledgment indicating that the handover process within the central unit has been approved.

12. The apparatus according to any of the preceding claims, wherein the message includes a timestamp indicating the timing of a second measurement report received by the distribution unit and causing a handover process within the central unit, and wherein the apparatus is configured to compare the timestamp with the timing of the measurement report indicating a handover process between central units, and to determine, based on the comparison, whether to perform the handover process between central units.

13. The apparatus according to any one of claims 1 to 12, wherein the intra-centralized unit switching process and the inter-centralized unit switching process are both switching processes of the same type: conditional switching process, layer 3 switching process, or layer 1 / layer 2 triggered mobility.

14. A method comprising: The distribution unit receives measurement reports for user equipment; The distribution unit determines to initiate an intra-centralized unit handover process based on the received measurement report, wherein initiation includes sending a message to the centralized unit controlling the distribution unit, the message being used to prevent concurrent intra-centralized unit handover processes and inter-centralized unit handover processes for the user equipment; as well as Based on the sent message, the distribution unit and the user equipment perform the intra-centralized unit handover process, or cancel the initiated intra-centralized unit handover process.

15. The method of claim 14, wherein in the absence of a response to the message from the central unit, the distribution unit performs a handover procedure within the central unit.

16. The method of claim 14, wherein the distribution unit waits for confirmation from the central unit when sending the message, and executes the intra-central unit handover process when it determines that the confirmation instructs the central unit to approve the intra-central unit handover process.

17. The method of claim 14, wherein the distribution unit waits for confirmation from the central unit when sending the message, and cancels the intra-central unit handover process when it determines that the confirmation indicates the central unit to reject the intra-central unit handover process.

18. The method according to any one of claims 14 to 17, further comprising: The distributed unit receives a second message from the centralized unit. The second message is used to prevent the concurrent intra-centralized unit switching process and inter-centralized unit switching process, and to cancel the intra-centralized unit switching process or another intra-centralized unit switching process.

19. The method of any one of claims 14 to 18, wherein the distribution unit associates the measurement report with a timestamp and includes the timestamp in the message.

20. A method comprising: The central unit receives a message from the distributed unit controlled by the central unit, the message indicating that the distributed unit intends to perform a handover process with the user equipment within the central unit; The centralized unit receives a measurement report for the user equipment, and the measurement report indicates the handover process between the centralized units. Based on the timing of the message and the measurement report, the central unit performs a central unit handover process based on the received measurement report and sends a second message to the distribution unit. The second message is used to prevent concurrent intra-central unit handover processes and inter-central unit handover processes for the user equipment, or the central unit determines not to perform the inter-central unit handover process in order to allow the intra-central unit handover process indicated by the message to be performed.

21. The method of claim 20, wherein if the measurement report is received before the message, the central unit performs the inter-central unit handover procedure based on the received measurement report, wherein the second message is a response to the message received from the distribution unit, and wherein the second message indicates that the central unit refuses to perform the intra-central unit handover procedure, the intra-central unit handover procedure being indicated by the message received from the distribution unit.

22. The method of claim 20, wherein if the measurement report is received before the message, the central unit performs the inter-central unit switching procedure based on the received measurement report, and wherein, The second message is an instruction to the distribution unit, indicating that the central unit is performing a handover process for the user equipment, and the second message prevents the distribution unit from initiating a concurrent handover process within the central unit.

23. The method of claim 20, wherein if the message is received before the measurement report, the central unit determines not to perform the central unit switching process based on the received measurement report.

24. The method of claim 23, wherein the central unit responds to the message by sending an acknowledgment indicating that the handover process within the central unit has been approved.

25. The method of any one of claims 20 to 24, wherein the message includes a timestamp indicating the timing of a second measurement report received by the distribution unit and causing a switching process within the central unit, and wherein the central unit compares the timestamp with the timing of the measurement report indicating a switching process between central units, and determines whether to perform the switching process between central units based on the comparison.

26. The method according to any one of claims 14 to 25, wherein both the intra-centralized unit switching process and the inter-centralized unit switching process are switching processes of the same type: conditional switching process, layer 3 switching process, or layer 1 / layer 2 triggered mobility.

27. A computer program product embodied on a computer-readable distribution medium and comprising program instructions that, when executed by a device, cause the device to perform the method according to any one of claims 14 to 26.

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